Positron Emission Tomography and Magnetic Resonance Imaging in Experimental Human Malaria to Identify Organ-Specific Changes in Morphology and Glucose Metabolism: A Prospective Cohort Study

Abstract

BAU : Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly: ackgroundPlasmodium vivax has been proposed to infect and replicate in the human spleen and bone marrow. Compared to PAU : PleasenotethatasperPLOSstyle; iftwodifferentspeciessharethesamegenus; theg lasmodium falciparum, which is known to undergo microvascular tissue sequestration, little is known about the behavior of P. vivax outside of the circulating compartment. This may be due in part to difficulties in studying parasite location and activity in life. Methods and findingsTo identify organ-specific changes during the early stages of P. vivax infection, we performed 18-F fluorodeoxyglucose (FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) at baseline and just prior to onset of clinical illness in P. vivax experimentally induced blood-stage malaria (IBSM) and compared findings to P. falciparum IBSM. Seven healthy, malaria-naive participants were enrolled from 3 IBSM trials: NCT02867059, ACTRN12616000174482, and ACTRN12619001085167. Imaging took place between 2016 and 2019 at the Herston Imaging Research Facility, Australia. Postinoculation imaging was performed after a median of 9 days in both species (n = 3 P. vivax; n = 4 P. falciparum). All participants were aged between 19 and 23 years, and 6/7 were male. Splenic volume (P.